1. Field of the Invention
This invention relates to editing typewriter systems of the kind which simultaneously make printed and magnetic records and have the capability of automatically and rapidly making printed copies of the magnetically recorded entries. More specifically, the present invention employs a novel recording unit arrangement at the typewriter instrument and a novel system for recording and replaying the desired characters.
2. Description of the Prior Art
Editing typewriter systems are well known and in commercial use. Such systems are comparatively expensive and require certain restraints in their operation. For instance, in known machines such as that disclosed in U.S. Pat. No. 3,413,624, the keyboard data and format instructions are stored in a tape and therefore they appear sequentially and operator coordination of the tape and text for preparation of error-free copy is difficult. One solution to that problem was disclosed in U.S. Pat. Nos. 3,756,365 and 3,788,441 (both assigned to the assignee of this application), but had an inherent weakness in that association of the magnetic card recording with the motion of the platen carriage resulted in variable density of the magnetic pattern. To avoid variable density of recording, a separate drive for the recording action of a magnetic head supported by the platen carriage was disclosed in U.S. Pat. No. 3,819,024, also assigned to the assignee of this application, but this requires structure of greater complexity. Accordingly, there is need of an improved machine for simultaneous preparation of typewritten and magnetic records with ease of editing by the operator, the magnetic record then being available for reproduction at the option of the operator.